Disable certain dropdown option based on row data, Line 161: Demo disables dropdown option with id:1 when row's tax field > 50

dropdown-conditional-disable.php

<?php 
/**
 * PHP Grid Component
 *
 * @author Abu Ghufran <gridphp@gmail.com> - http://www.phpgrid.org
 * @version 2.0.0
 * @license: see license.txt included in package
 */

// include db config
include_once("../../config.php");

// include and create object
include(PHPGRID_LIBPATH."inc/jqgrid_dist.php");

// Database config file to be passed in phpgrid constructor
$db_conf = array( 	
					"type" 		=> PHPGRID_DBTYPE, 
					"server" 	=> PHPGRID_DBHOST,
					"user" 		=> PHPGRID_DBUSER,
					"password" 	=> PHPGRID_DBPASS,
					"database" 	=> PHPGRID_DBNAME
				);
				
$g = new jqgrid($db_conf);

$grid["rowNum"] = 10; // by default 20
$grid["sortname"] = 'id'; // by default sort grid by this field
$grid["caption"] = "Invoice Data"; // caption of grid
$grid["autowidth"] = true; // expand grid to screen width
$grid["multiselect"] = true; // allow you to multi-select through checkboxes
$grid["form"]["position"] = "center";
$g->set_options($grid);

$g->set_actions(array(	
						"add"=>true, // allow/disallow add
						"edit"=>true, // allow/disallow edit
						"delete"=>true, // allow/disallow delete
						"view"=>true, // allow/disallow delete
						"rowactions"=>true, // show/hide row wise edit/del/save option
						"search" => "advance", // show single/multi field search condition (e.g. simple or advance)
						"showhidecolumns" => false
					) 
				);

// you can provide custom SQL query to display data
$g->select_command = "SELECT i.id, invdate , i.client_id,
						i.note, i.total, i.closed, i.tax FROM invheader i
						INNER JOIN clients c ON c.client_id = i.client_id";

// you can provide custom SQL count query to display data
$g->select_count = "SELECT count(*) as c FROM invheader i
						INNER JOIN clients c ON c.client_id = i.client_id";

// this db table will be used for add,edit,delete
$g->table = "invheader";

$col = array();
$col["title"] = "Id"; // caption of column
$col["name"] = "id"; // grid column name, must be exactly same as returned column-name from sql (tablefield or field-alias) 
$col["width"] = "10";
$col["editable"] = true;
$col["hidden"] = true;
$cols[] = $col;

$col = array();
$col["title"] = "Date";
$col["name"] = "invdate"; 
$col["width"] = "50";
$col["editable"] = true; // this column is editable
$col["editoptions"] = array("size"=>20, "defaultValue"=>"02/02/2013"); // with default display of textbox with size 20
$col["editrules"] = array("required"=>true, "edithidden"=>true); // and is required
$col["formatter"] = "date"; // format as date
$col["formatoptions"] = array("srcformat"=>'Y-m-d',"newformat"=>'d/m/Y'); // http://docs.jquery.com/UI/Datepicker/formatDate
$cols[] = $col;
		
$col = array();
$col["title"] = "Client";
$col["name"] = "client_id";
$col["width"] = "100";
$col["editable"] = true; // this column is not editable
$col["edittype"] = "lookup"; // this column is not editable
$col["editoptions"] = array("table"=>"clients", "label"=>"name", "id"=>"client_id"); // this column is not editable
$col["search"] = false; // this column is not searchable
$cols[] = $col;

$col = array();
$col["title"] = "Note";
$col["name"] = "note";
# $col["width"] = "300"; // not specifying width will expand to fill space
$col["sortable"] = false; // this column is not sortable
$col["search"] = false; // this column is not searchable
$col["editable"] = true;
$col["edittype"] = "textarea"; // render as textarea on edit
$cols[] = $col;


$col = array();
$col["title"] = "Tax";
$col["name"] = "tax";
$col["width"] = "50";
$col["isnull"] = true;
$col["editable"] = true;
$cols[] = $col;

$col = array();
$col["title"] = "Total";
$col["name"] = "total";
$col["width"] = "50";
$col["editable"] = true;
$col["firstsortorder"] = "desc";
$col["formatter"] = "number";

// To mask password field, apply following attribs
# $col["edittype"] = "password";
# $col["formatter"] = "password";

// default render is textbox
// $col["editoptions"] = array("value"=>'10');

// can be switched to select (dropdown)
// $col["edittype"] = "select"; // render as select
// $col["editoptions"] = array("value"=>'10:$10;20:$20;30:$30;40:$40;50:$50'); // with these values "key:value;key:value;key:value"

$cols[] = $col;

$col = array();
$col["title"] = "Closed";
$col["name"] = "closed";
$col["width"] = "50";
$col["editable"] = true;
$col["formatter"] = "checkbox"; // render as checkbox
$col["edittype"] = "checkbox"; // render as checkbox
$col["editoptions"] = array("value"=>"1:0"); // with these values "checked_value:unchecked_value"
$col["editrules"] = array("readonly"=>true, "readonly-when"=>"unchecked");
$cols[] = $col; 

// pass the cooked columns to grid
$g->set_columns($cols);

// generate grid output, with unique grid name as 'list1'
$out = $g->render("list1");
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html>
<head>
	<link rel="stylesheet" type="text/css" media="screen" href="../../lib/js/themes/redmond/jquery-ui.custom.css"></link>	
	<link rel="stylesheet" type="text/css" media="screen" href="../../lib/js/jqgrid/css/ui.jqgrid.css"></link>	
	<script src="../../lib/js/jquery.min.js" type="text/javascript"></script>
	<script src="../../lib/js/jqgrid/js/i18n/grid.locale-en.js" type="text/javascript"></script>
	<script src="../../lib/js/jqgrid/js/jquery.jqGrid.min.js" type="text/javascript"></script>	
	<script src="../../lib/js/themes/jquery-ui.custom.min.js" type="text/javascript"></script>
</head>
<body>

	<div style="margin:10px">
	<?php echo $out?>
	</div>

	<script>
	setTimeout(function(){
		link_select2 = function(id)
		{
			var gid = jQuery(".ui-jqgrid").attr("id").replace("gbox_","");
			var grid = jQuery("#"+gid);
			var selectedRow = grid.getGridParam('selrow');
			var row =  $('#list1').getRowData(selectedRow);

			if (id == 'client_id')
			{
				if (row.tax > 50)
					$('select[name='+id+'].editable option[value="1"], select[id='+id+'] option[value="1"]').prop('disabled',true);
			}

			if(!jQuery().select2) return;
			
			$('select[name='+id+'].editable, select[id='+id+']').select2({onSelect: function(){ jQuery(this).trigger('change'); }});
			$(document).unbind('keypress').unbind('keydown');
		}
	},500);
	</script>	

</body>
</html>